code: def test_simple(self, mock_handler):
      # dataset, string values
      df = pd.DataFrame(range(1, 50), columns=["a"])
      df["b"] = 50 - df.a
      df["c"] = round((df["a"] * 3 + df["b"]) / 50)
  
      self.set_handler(mock_handler, name="pg", tables={"df": df})
  
      # create project
      self.run_sql("create database proj")
  
      # create predictor
      self.run_sql(
          """
             create model proj.modelx
             from pg (select * from df)
             predict c
             using 
               submodels = [{
                  "module": "Regression",
                  "args": {}
               }]
          """
      )
      self.wait_predictor("proj", "modelx")
  
      # run predict
      ret = self.run_sql(
          """
             SELECT p.*
             FROM pg.df as t 
             JOIN proj.modelx as p
             where t.c=1
          """
      )
      avg_c = pd.to_numeric(ret.c).mean()
      # value is around 1
      assert (avg_c > 0.9) and (avg_c < 1.1)
  
      # test describe
      ret = self.run_sql("describe proj.modelx")
      assert len(ret) == 1
      for col in (
          "accuracies",
          "column_importances",
          "outputs",
          "inputs",
          "model",
      ):
          assert col in ret.columns
  
      ret = self.run_sql("describe proj.modelx.model")
      for col in [
          "name",
          "performance",
          "training_time",
          "selected",
          "accuracy_functions",
      ]:
          assert col in ret.columns
  
      ret = self.run_sql("describe proj.modelx.features")
      for col in ["column", "type", "encoder", "role"]:
          assert col in ret.columns
  
      ret = self.run_sql("describe proj.modelx.ensemble")
      assert "ensemble" in ret.columns
  
file_path: mindsdb/tests/unit/ml_handlers/test_lightwood.py
imports: import time
  from unittest.mock import patch
  import pandas
  from mindsdb_sql import parse_sql
  from tests.unit.executor_test_base import BaseExecutorTest
label_desc: Use image node_id 3 for calling the TestLW obj's underlying member method code with example usage: obj.test_simple(mock_handler) without return types